Absorption spectra of dipolar Frenkel excitons in two-dimensional lattices with configurational disorder: Long-range interaction and motional narrowing effects

© 2000 American Institute of Physics. The authors thank R. Brito for helpful comments. Work at Madrid was supported by CAM under Project No. 07N/ 0034/98. V.A.M. thanks UCM for the support under Saba´ticos Complutense.
We present results of numerical simulations of optical absorption line shape of Frenkel excitons in two-dimensional disordered lattices. Disorder is generated by Gaussian randomness in the molecular positions. The intersite interaction is considered to be of dipole origin, including coupling to far neighbors. Results of simulations are compared with those obtained in the frame of the nearest-neighbor approximation, showing remarkable differences in the absorption line shape. The motional narrowing effect is found to be essentially different from that previously reported for the case of diagonal disorder as well as for that produced by randomness in nearest-neighbor hopping integrals.
CAM
UCM-Sabáticos Complutenses
Depto. de Física de Materiales
Fac. de Ciencias Físicas
TRUE
pub